Dynamic audio parameter adjustment using touch sensing

ABSTRACT

An audio communications device has a handset in which a touch sensing ear piece region is coupled to an acoustic leakage analyzer. The acoustic leakage analyzer is to analyze signals from the touch sensing ear piece region and on that basis adjust an audio processing parameter. The latter configures an audio processor which generates an audio receiver input signal for the device. Other embodiments are also described and claimed.

An embodiment of the invention relates to techniques for adjusting audioparameters in a communications device for improving tolerance toacoustic leakage. Other embodiments are also described.

BACKGROUND

People have long been accustomed to making telephone calls using ahandset whose earpiece portion the user typically presses up against herear (in order to better hear the voice of the other party.) As mobilephones became prevalent, the acoustic system that delivers sound to theuser's ear was faced with a variety of environmental conditions, inparticular varying levels of background noise. A mobile phone might beused in a quiet room until the user walks outside to a noisy street. Theintelligibility of sound from the earpiece (produced by the so-calledreceiver or earpiece loud speaker) is reduced when there is a raisedambient noise level. In addition, it is typical for the user in thatcase to want to press the handset more firmly to his ear. If thereceiver is too loud, the user may pull back or lift off the handset tomove the earpiece away from her ear.

The earpiece has been conventionally designed in such a way that itproduces good sound pressure and quality, when it is mostly sealed or ina particular sealing condition against the user's ear. If there is alarger gap, that is a larger leak between the earpiece and the user'sear, this usually causes a significant weakening of the sensed soundpressure. Manufacturers try to ensure that the volume and frequencydistribution of the sound from the earpiece is in accordance with theirspecification, in actual or real operating conditions where the earpieceis rarely completely sealed against the user's ear. In other words, thehandset has to have the ability to tolerate or adapt to such acousticleakage in its earpiece region.

Typically, several techniques have been used to improve acoustic leaktolerance. In one technique, a loose coupling is arranged to thereceiver (which produces the sound waves in the earpiece region). Thereceiver in that case is acoustically loaded by a relatively largevolume that is as large as possible. Another way to improve leaktolerance may be to lower the acoustic output impedance of the earpiecearrangement by using an acoustic return path.

In another solution, an acoustic sensor is added to measure the soundpressure that is present in the acoustic interspace between the earpieceregion and the user's ear. A control circuit compensates for themeasured loss in sound pressure that is caused by an acoustic leak, tokeep the subjective impression of the loudness level (and thus theintelligibility of the speech signal), always approximately in the samerange. The subjective impression of the loudness level depends not onlyon the total power of the acoustic signal, but also on the distributionof the energy within its signal spectrum.

SUMMARY

In accordance with an embodiment of the invention, the handset of anaudio communications device has a touch sensing earpiece region. Anacoustic leakage analyzer is coupled to the touch sensing earpieceregion, to analyze signals from the region and on that basis adjust anaudio processing parameter (that is used by an audio processor togenerate an audio receiver input signal for the device). This allows thedevice to automatically adjust the audio processing parameter tocompensate for acoustic leakage between the user's ear and the earpieceregion.

The above summary does not include an exhaustive list of all aspects ofthe present invention. It is contemplated that the invention includesall systems and methods that can be practiced from all suitablecombinations of the various aspects summarized above, as well as thosedisclosed in the Detailed Description below and particularly pointed outin the claims filed with the application. Such combinations haveparticular advantages not specifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention are illustrated by way of example andnot by way of limitation in the figures of the accompanying drawings inwhich like references indicate similar elements. It should be noted thatreferences to “an” or “one” embodiment of the invention in thisdisclosure are not necessarily to the same embodiment, and they mean atleast one.

FIG. 1 shows an example audio communications device in use, including animprint of the user's ear activated in the touch sensing earpieceregion.

FIG. 2 is a block diagram of some relevant functional components of thecommunications device.

FIG. 3 depicts an example user ear imprint pattern that may be stored inthe audio communications device, for use by an acoustic leakageanalyzer.

FIG. 4 is a block diagram of relevant functional components of the audiocommunications device, and, in particular, an example set of audioprocessing components that may be controlled by the acoustic leakageanalyzer

FIG. 5 depicts another embodiment of the audio communications device,where a touch sensing panel extends from a lower end portion to an upperend portion of the handset.

DETAILED DESCRIPTION

Several embodiments of the invention with reference to the appendeddrawings are now explained. Whenever the shapes, relative positions andother aspects of the parts described in the embodiments are not clearlydefined, the scope of the invention is not limited only to the partsshown, which are meant merely for the purpose of illustration. Also,while numerous details are set forth, it is understood that someembodiments of the invention may be practiced without these details. Inother instances, well-known circuits, structures, and techniques havenot been shown in detail so as not to obscure the understanding of thisdescription.

FIG. 1 shows an example of a handset 10 of an audio communicationsdevice in use. Some relevant physical and functional components of thedevice are shown in FIG. 2. The handset 10 has a housing in which areintegrated a touch sensing earpiece region 11 located above a userdisplay region 12. The earpiece 11 includes a sound emitting surface 14.The sound emitting surface 14 may be part of or may hide a receiver 22(also referred to as an earpiece speaker). The earpiece region 11 may beformed at an upper end of a touch sensitive panel. The earpiece region11 should be able to detect the imprint of the user's ear against itssurface. The region 11 includes one or more sensors for detectingproximity of an object, in this case the user's ear. These sensors maybe based on resistive sensing, surface acoustic wave sensing, forcesensing (e.g., strain gauge), optical sensing, and/or capacitivesensing. The sensors may be dispersed about the region 11. Each sensormay be represented by two or more coordinates, such as an x, y pair. Inmany cases, the sensors may be arranged in a grid of columns and rows.Position signals may be generated by the region 11 when, for example, aportion of the user's ear comes sufficiently close to or essentiallycontacts the grid of sensors, and then moves across the grid.

The user display region 12 may be part of a solid state display panelsuch as an LCD panel typically used in a communications handset. Theuser display region 12 may be in a separate physical component than thetouch sensing panel in which the earpiece region 11 is formed.

Below the user display region 12 is a user input region 13 shown in thisexample as having a physical keypad that is typical for a cellular phoneor smart phone. Below the user input region 13 at a lower end of thehandset is a sound pickup surface 15. The sound pickup surface 15 may bepart of, or may conceal behind it, a microphone 26 such as one that isused in a typical cellular phone or smart phone, to pick up the voice ofa near end user during a two-way communications session (also referredto as a call).

The call allows the near end user to speak to and hear the voice of afar end user in real-time, over a communications network. The call maybe a voice-only session, or it may be a video session (including bothvoice and images). In the example of FIG. 1, the call is identified by“connected” being displayed in the user display region 12, inassociation with the address of or an identification associated with thefar end user (here a 10 digit telephone number) as well as the elapsedtime. The communications session may be a wireless call, such as onethat is performed by the handset 10 using a cellular network protocol ora wireless local area network protocol, while communicating with a basestation in the network through a communication network interface 24 (seeFIG. 2). The communication network interface 24 serves to interfacedownlink and uplink channel signals with a communications network, suchas a cellular telephone network, a plain old telephone system network,or a wired local area network.

The audio communications device includes a downlink audio signalprocessor 23 (see FIG. 2) to generate a downlink channel audio receiverinput signal that is converted to sound through the sound emittingsurface 14 in the earpiece region 11. The input signal to the receiver22 has characteristics that are governed by one or more audio processingparameters of the audio processor 23. Adjusting such parameters toincrease intelligibility for the near end user affects the total powerof the acoustic signal emitted from the sound emitting surface 14, aswell as the distribution of the energy within its signal spectrum.

FIG. 1 shows that the touch sensing earpiece region 11 contains severaltouch-activated regions 16. In particular, in this example, there arethree separate or isolated regions 16 that have been produced as aresult of the earpiece region 11 being essentially in contact withportions of the near end user's ear during the call. Note, however, thatthis so-called imprint of the user's ear need not actually be displayedto the user—FIG. 1 only shows the touch activated regions 16 forpurposes of understanding the invention.

The illustrated touch activated regions 16 are each examples of separateregions located around the sound emitting surface 14. The regions 16 areseparate in that they are not linked, that is have no gaps ornon-activated regions between them. In other words, each region 16 maybe deemed an island. In most instances, the manner in which the user'sear contacts the ear piece region 11 produces several separate regions,rather than a single closed region around the sound emitting surface 14.However, it may be expected that where the user is pressing the handset10 very strongly against her ear, a single closed region might bedetected. The latter could be associated with the situation where thedetected seal is considered to be very good or complete.

An acoustic leakage analyzer 28 that is coupled to the touch sensing earpiece region 11 analyzes sensor signals from the region 11, and inparticular the pattern of the touch-activated regions 16, and on thatbasis adjusts one or more audio processing parameters. The parametersare automatically adjusted to compensate for acoustic leakage betweenthe near end user's ear and the earpiece region. How and which audioprocessing parameters to adjust may be determined in advance. This maybe based on, for example, laboratory experiments that evaluate thequality of the sound heard by the near end user (from the sound emittingsurface 14) for different levels of acoustic leakage detected (using atouch sensing panel in which the earpiece region 11 is formed). Variousinstances of a near end user pressing the handset 10 against her ear canbe tested. For each instance a suitable set of adjustments to one ormore parameters can be selected and stored in the manufactured orend-user purchased specimens of the device.

The block diagram of FIG. 2 shows some additional relevant functionalcomponents of the communications device. An uplink audio signalprocessor 25 performs various conventional tasks on the uplink signalfrom the microphone 26 and then delivers an uplink channel audio signalto a communication network interface 24. It may also provide sidetone tothe downlink processor 23. For the downlink channel, the downlink audiosignal processor 23 receives a downlink channel signal from thecommunication network interface 24, containing the voice of the far enduser, and processes that signal into an input audio signal to drive thereceiver 22. The signal processors 23, 25 may include digital and analogcircuit components, and may also include programmable circuitry asneeded to produce a comfortable sound for the two-way communicationsession between the near end user and the far end user.

The intelligibility of sound heard by the near end user may be improvedas follows. First, the acoustic leakage analyzer 28 analyzes signalsfrom the touch sensing earpiece region 11, which may indicate whichportions of the region 11 have been activated due to essentially touch(which is also understood to include near touch), by the user's ear. Theanalyzer 28 detects one or more separate touch-activated regions 16 andmay then compare these to a previously stored pattern to, for example,determine how well the earpiece region is sealed against the user's ear.FIG. 3 shows an example pattern 30, for example, in terms of activatedsquares or sensors in a grid representing the surface of the earpieceregion 11, that may be stored in a memory of the device. A rough measureof the level of sealing achieved in a given instance may be the extentto which the active grid elements enclose or encircle the central regionof the grid (where the sound emitting surface 14 is located). Inaddition, the enclosed area (or the roughly enclosed area) may indicatethe size of the user's ear and therefore the volume of an acousticcavity that is formed in front of the earpiece region 11. Depending uponthe experimental results, certain arrangements of active grid elementsmay be found to represent better acoustic seal conditions. Such findingscould be stored in the communications device, readily accessible by theacoustic leakage analyzer 28 in real time so that the audio parametersof the downlink audio signal processor 23 may be updated dynamicallyduring a call, as the user's ear seal level changes as the userrepositions the handset 10 against her ear.

Another factor that may be used by the acoustic leakage analyzer 28 (todetermine how to essentially dynamically tune the frequency content andtotal power of the sound emitted from the earpiece region) is a measureof how hard the user is pushing the handset 10 against her ear. Thisfactor may help indicate, for example, the depth of the acoustic cavityformed in front of the earpiece region. A pressure sensor (pressure orforce transducer such as a strain gauge) may be incorporated into thehousing of the handset 10, e.g. on the front face, or on the back facewhere the user grips the handset 10, to provide a measure of thephysical force generated by the user pressing the handset 10 against herear.

Once an estimated level of acoustic leakage has been determined, theacoustic leakage analyzer 28 may compensate for the acoustic leakageusing any one or more of several conventional techniques. Referring nowto FIG. 4., an example set of audio processing components (as part ofthe downlink audio processor 23) that may be adjusted by the acousticleakage analyzer 28 are shown. The audio processor 23 in this instancecontains a chain of components or stages that operate on the downlinkchannel audio signal (together with a sidetone signal), to produce aninput signal for driving the receiver 22. In this example, the audioprocessor 23 includes an equalization block, an expander block, acompressor block, a noise reducer block, a gain setting unit, anautomatic gain control (AGC) block, and a power amplifier block.Changing the loudness or volume of the receiver sound output may beperformed by signaling the power amplifier; tuning an audio frequencyresponse parameter to modify overall frequency response may be obtainedby signaling any one or more of the equalization, compander (expanderand compressor), noise reducer, and AGC blocks. Note that changing oneor more of these audio processing parameters may generally be expectedto result in changing both the sound pressure level and the frequencycontent or spectral characteristics of the acoustic output of thereceiver (which is delivered to the user's ear from the sound emittingsurface 14). In one example, a parameter of the equalization blockand/or the expander block may be adjusted so as to boost a frequencyresponse range that is below one kHz, relative to a frequency responserange that is above one kHz. It has been found that this lower frequencyrange suffers more than the upper frequency range as the acoustic sealworsens. Other parameter adjustments are possible. Also, note that notall of the audio processing components depicted in FIG. 4 are needed toprovide the user with a comfortable sound in every instance.

Turning now to FIG. 5., another embodiment of the audio communicationsdevice is shown, where in this case a touch sensing panel 42 extendsfrom a lower end portion 46 to an upper end portion (being the ear pieceregion 11) of the outer housing or case of the handset 10. This iscontrast to the embodiment of FIG. 1 where the touch sensing panel maybe confined to just the ear piece region 11 at the upper end portion ofthe handset 10. Another difference is that the user input region 13 ofFIG. 1 is implemented as a set of virtual keypad components in the userinput and display region 44 of the touch panel 42. In FIG. 5, the soundemitting surface 14 which is in the ear piece region 11 encompasses areceiver acoustic opening 48 that may be formed through the touchsensing panel 42. The user input and display region 44 is formed withinthe touch sensing panel 42, in effect replacing the user display region12 and the user input region 13 of the embodiment of FIG. 1. The virtualtelephone keypad may appear when a telephony application has beenlaunched by the user of the handset 10. In addition, in the embodimentof FIG. 5, the sound pickup surface 15 is formed not on the front facebut on a side of the outer housing or case, encompassing a microphoneacoustic opening 49 as shown. The outer housing or case in this casealso includes a loud speaker acoustic opening 47 which would be used forplaying sounds though a speaker phone function of the handset 10.

To conclude, various aspects of a technique for dynamically(automatically) adjusting one or more audio parameters of acommunications device to compensate for acoustic leakage have beendescribed. It should be noted that the functional components describedabove may be arranged in different physical forms, for purposes ofimproving the manufacturability or other practical considerations.Several functional components may be integrated into a single integratedcircuit (IC) chip or package, while a single functional component couldbe distributed across multiple IC chips or packages. For example, theacoustic leakage analyzer 28 may be implemented as a programmedapplications processor (AP) that is integrated in the handset 10; someof the audio processing components shown in FIG. 4 could be implementedin a programmed cellular or wireless communications baseband processor,while others such as the power amplifier could be part of a separateaudio codec chip.

An embodiment of the invention may also be in the form of amachine-readable medium having stored thereon instructions which programone or more processors that make up the audio communications device, toperform some of the operations described above, such as detecting touchsensed imprints of the user's ear and adjusting audio processingparameters to compensate for acoustic leakage. In other embodiments,some of these operations might be performed by specific hardwarecomponents that contain hardwired logic. Those operations mightalternatively be performed by any combination of programmed dataprocessing components and fixed hardware circuit components.

A machine-readable medium may include any mechanism for encoding orstoring information in a form readable by a machine (e.g., a computer),such as Compact Disc Read-Only Memory (CD-ROMs), Read-Only Memory(ROMs), Random Access Memory (RAM), and Erasable Programmable Read-OnlyMemory (EPROM).

While certain embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat the invention is not limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those of ordinary skill in the art. For example, although thediscussion above focuses on a call between a near end user and a far enduser, the call could also include additional participants (such as in amulti-party conference call) whose voice signals would be mixed into thedownlink channel of the near end user. Also, although the touch sensingregion 11 is shown as being essentially flat, an alternative would be tohave one or more curved portions therein. Finally, although twodifferent versions of a handset 10 are shown in FIG. 1 and in FIG. 5,the invention may also be implemented in other types of handsets, suchas cellular phone handsets that have a clamshell type structure. Thedescription is thus to be regarded as illustrative instead of limiting.

1. A machine-implemented method for operating an audio communicationsdevice, comprising: during a call that is being performed using theaudio communications device, automatically detecting an imprint of auser's ear against a region around a sound emitting surface of thedevice using a touch sensing surface, and adjusting an audio processingparameter of the device based on said detection to compensate foracoustic leakage between the user's ear and the region around the soundemitting surface.
 2. The method of claim 1 wherein said detectingcomprises: detecting a plurality of separate touch-activated regionsaround the sound emitting surface, each of the separate regions beingcontiguous.
 3. The method of claim 1 wherein said adjusting an audioprocessing parameter of the device comprises: adjusting a plurality ofparameters of an audio signal processor whose input is to receive adownlink audio signal and a sidetone signal, to change sound pressurelevel and spectral content of an acoustic signal that is delivered tothe user's ear.
 4. The method of claim 3 wherein said adjusting aplurality of parameters comprises one of: adjusting a gain setting unit;adjusting an automatic gain control (AGC) unit; adjusting anequalization filter; adjusting a noise suppressor or noise canceller;adjusting a compander; adjusting a compressor; and adjusting anexpander.
 5. The method of claim 3 wherein said adjusting a plurality ofparameters comprises: boosting a frequency response range that is below1 kHz, relative to a frequency response range that is above 1 khz, whencompensating for a transition from a more sealed condition to a lesssealed condition.
 6. The method of claim 3 wherein said adjusting aplurality of parameters comprises: cutting back a frequency range thatis below 1 kHz, relative to a frequency response range that is above 1khz, when compensating for a transition from a less sealed condition toa more sealed condition.
 7. An audio communications device, comprising:a handset having a touch sensing earpiece region; an audio processor togenerate an audio receiver input signal; and an acoustic leakageanalyzer coupled to the touch sensing earpiece region to analyze signalsfrom the region and on that basis adjust an audio processing parameterof the audio processor.
 8. The audio communications device of claim 7wherein the handset comprises a touch sensitive screen in which thetouch sensing earpiece region is formed at an upper end thereof and auser input and display region is formed below the earpiece region. 9.The audio communications device of claim 8 wherein the acoustic leakageanalyzer is to detect a plurality of separate touch-activated regionsfrom the touch sensing earpiece region.
 10. The audio communicationsdevice of claim 9 wherein the acoustic leakage analyzer is to comparethe touch-activated regions to a previously stored pattern and on thatbasis determine the level of acoustic sealing present around the touchsensing earpiece region.
 11. The audio communications device of claim 10wherein the acoustic leakage analyzer is to adjust the audio processingparameter to change one of loudness and spectral content of an acousticsignal emitted from a sound emitting surface of the touch sensingearpiece region, based on the determined level of acoustic sealing. 12.The audio communications device of claim 11 wherein the acoustic leakageanalyzer is to boost a frequency response range of the audio signalprocessor that is below 1 kHz, relative to a frequency response rangethat is above 1 kHz, based on the determined level of acoustic sealingindicating a transition from a more sealed condition to a less sealedcondition.
 13. The audio communications device of claim 11 wherein theacoustic leakage analyzer is to cut back a frequency response range ofthe audio signal processor that is below 1 kHz, relative to a frequencyresponse range that is above 1 kHz, based on the determined level ofacoustic sealing indicating a transition from a less sealed condition toa more sealed condition.
 14. The audio communications device of claim 10wherein the audio signal processor comprises one of the following whosefrequency response is adjusted by the acoustic leakage analyzer: a gainsetting unit, an automatic gain control unit, an equalization filter, anoise suppressor or noise canceller, a compressor, a compander, and anexpander.
 15. An article of manufacture comprising: a machine-readablemedium having stored therein program code that configures an audiocommunications device, having a touch sensing earpiece region, to detectan ear imprint from the earpiece region and on that basis adjust anaudio processing parameter of the device to compensate for acousticleakage at the earpiece region.
 16. The article of manufacture of claim15 wherein the program code configures the communications device to bothdetect the ear imprint and adjust the audio processing parameter duringa call that is being performed using the device.
 17. The article ofmanufacture of claim 16 wherein the program code configures thecommunications device to detect the ear imprint by analyzing signalsfrom the earpiece region relative to a stored pattern of signals and onthat basis determine that the earpiece region has transitioned between amore sealed condition to a less sealed condition.
 18. The article ofmanufacture of claim 16 wherein the program code configures thecommunications device to adjust the audio processing parameter based ona determination that the earpiece region has transitioned betweendifferent acoustic seal conditions.